Two Kenyan police officers and a civilian were killed when rioters hurled a grenade at officers in the port city of Mombasa on Tuesday after two days of violence over the killing of a radical Muslim cleric.
The riots broke out on Monday after Aboud Rogo, accused by the United States of helping al Qaeda-linked Islamist militants in Somalia, was shot dead. Gunmen sprayed Rogo's car with bullets in an attack many Muslims in Mombasa blamed on the police, who denied involvement.
Prolonged trouble in Mombasa would hit Kenya's vital tourism industry, already damaged by the kidnappings of Western women tourists from beach resorts by Somali gunmen, at the height of the tourist season.
"Right now we have closed all our tourists in the hotels. We can't take them on safaris, we can't take them on tours of cultural sights... because it is unsafe," said Titus Kangangi, owner of the Platinum hotel just north of Mombasa.
Mohammed Hersi, who runs the Whitesands Hotel, the largest resort on the coast, said tourists were worried. "It's tricky to even take them or pick them from the airport because the main highway from the airport is the epicenter of the chaos."
The unrest could also knock trade and transport to Kenya's landlocked neighbors. Rwanda and Uganda rely on Mombasa port for imports of food, consumer goods and fuel.